Safari compat fix (capture group preserving version)

[lionel-rowe]

Fixes #143
Fixes #142

From my comment on #143:

Current fix gives wrong capture group results, as there are more capture groups in the lookaround-supporting regex than there are in the compat-mode regex:

const OriginalRegExp = globalThis.RegExp;

class SafariRegExp extends OriginalRegExp {
    constructor(pattern, flags) {
        super(pattern, flags)
        if (String(pattern).includes('(?<=')) {
            throw new SyntaxError('idk what (?<= even means')
        }
    }
}

globalThis.RegExp = SafariRegExp

const anchorme = (await import('https://esm.sh/v135/anchorme@3.0.8')).default
console.info(
    anchorme.list(
        `https://example.xyz example.com user@email.com file:///filename.txt 192.168.1.1`,
        false,
    )
)

// expected:
[
	{ start: 0, end: 19, string: 'https://example.xyz', isURL: true, protocol: 'https://', /* ... */ },
	{ start: 20, end: 31, string: 'example.com', isURL: true, protocol: undefined, /* ... */ },
	{ start: 32, end: 46, string: 'user@email.com', isEmail: true, local: 'user', /* ... */ },
	{ start: 47, end: 67, string: 'file:///filename.txt', isFile: true, protocol: 'file:///', /* ... */ },
	{ start: 68, end: 79, string: '192.168.1.1', isURL: true, protocol: undefined, /* ... */ },	
]
// actual:
[
	{ start: 0, end: 19, string: 'https://example.xyz', reason: 'unknown' },
	{ start: 20, end: 31, string: 'example.com', reason: 'unknown' },
	{ start: 32, end: 46, string: 'user@email.com', reason: 'unknown' },
	{ start: 47, end: 67, string: 'file:///filename.txt', isURL: true, protocol: undefined, /* ... */ },
	{ start: 68, end: 79, string: '192.168.1.1', reason: 'unknown' },	
]